Despite increasing risk for HIV infection, heterosexuals, especially those in steady relationships, continue to practice high levels of risky sexual behavior. Sexual risk-reduction interventions targeting heterosexual couples are warranted. However, several qualitative, conceptual, and methodological issues must be resolved prior to developing efficacious programs. This application requests supports to conduct an in-depth formative study of the barriers and facilitators of safer sex negotiation and behavior among heterosexually active, unmarried couples, ages 18-35 recruited from two inner-city community sites. The feasibility of, and optimal strategy for, recruiting couples to participate in a sexual risk- reduction intervention will also be assessed. Fifty couples (n=100) will be recruited to participate in an individual sexual behavior assessment. Quantitative and qualitative research methods will be employed to obtain descriptive and contextual information about participants' sexual behavior both within (intradyadic) and outside of (extradyadic) the primary relationship. Participants will first be interviewed separately, then interviewed jointly and asked to resolve discrepancies in their respective reports of overt, intradyadic behavior (e.g., condom use). Reported extradyadic and less overt intradyadic behavior (e.g., woman's use of a covert birth control method) will remain confidential and will not be discussed in the joint interview. Eighteen additional couples (n=36) will be recruited to participate in one of three open-ended focus groups (one mixed-gender, one women-only, one men-only). Results of this formative study will be used to (a) obtain a better understanding of the dynamic and contextual factors facilitating and impeding safer sex negotiation and behavior among heterosexual couples, (b) guide development of a pilot sexual risk-reduction intervention which addresses the dynamic and contextual components of couples' safer sex negotiation and decision- making identified in this study, and (c) examine the interpartner concordance of reported sexual behavior, and compare various strategies for computing partner data in order to determine the effect of discrepancies on study results.